Answer: B. The element called tin is a metal with the chemical symbol Sn.
Explanation:
A is incorrect because Ni is Nickel, not Niobium.
C is incorrect because Carbon is a nonmetal and its symbol is C, not Cr.
D is incorrect because Copper's symbol is Cu, not Ce.
E is incorrect because As is the symbol for Arsenic, not Astatine.
Answer:
An unknown being weighed is hygroscopic. - operative error
One component of a mixture being analyzed quantitatively by gas chromatography reacts with the column packing. - methodic error
The tip of the pipet used in the analysis is broken. - instrumental error
In measuring the same peak heights of a chromatogram, two technicians each report different heights - operative error
Explanation:
In chemical analysis, operative errors are that largely introduced into the measurement because of variation of personal judgements of analysts. It is also a personal error that emanates solely due to the analyst.
A methodic error arises as a result of adopting defective experimental methods. For example, a column packing that reacts with a component of the mixture is used in the gas chromatography.
Instrument error refers to the error of a measuring instrument, for instance, the use of a pipette with a broken tip.
Answer:
- <u><em>Option a. 6200 K</em></u>
Explanation:
<u>1) Data:</u>
- V₁ = 0.66 liter
- P₁ = 42.9 mmHg
- T = 261.2 K
- T₂ = ?
- V₂ = 7.63 liter
- P₂ = 872.15 mmHg
<u>2) Formula:</u>
Combined law of gases:
<u>3) Solution:</u>
T₂ = P₂ V₂ T₁ / (P₁ V₁)
T₂ = 872.15 mmHg × 7.63 liter × 261.2 K / ( 424.9 mmHg × 0.66 liter)
T₂ = 6198 K
- Rounding to 2 significant figures, that is 6200 K, which is the first choice.
